aboutsummaryrefslogtreecommitdiffstats
path: root/arch/x86/kernel/cpu/bugs.c
AgeCommit message (Collapse)Author
2015-05-19x86/fpu: Move various internal function prototypes to fpu/internal.hIngo Molnar
There are a number of FPU internal function prototypes and an inline function in fpu/api.h, mostly placed so historically as the code grew over the years. Move them over into fpu/internal.h where they belong. (Add sched.h include to stackprotector.h which incorrectly relied on getting it from fpu/api.h.) fpu/api.h is now a pure file that only contains FPU APIs intended for driver use. Reviewed-by: Borislav Petkov <bp@alien8.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-19x86/fpu: Rename i387.h to fpu/api.hIngo Molnar
We already have fpu/types.h, move i387.h to fpu/api.h. The file name has become a misnomer anyway: it offers generic FPU APIs, but is not limited to i387 functionality. Reviewed-by: Borislav Petkov <bp@alien8.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-19x86/fpu: Factor out the FPU bug detection code into fpu__init_check_bugs()Ingo Molnar
Move the boot-time FPU bug detection code to the other FPU boot time init code in fpu/init.c. No change in code size: text data bss dec hex filename 13044568 1884440 1130496 16059504 f50c70 vmlinux.before 13044568 1884440 1130496 16059504 f50c70 vmlinux.after Reviewed-by: Borislav Petkov <bp@alien8.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-06-06x86: Get rid of ->hard_math and all the FPU asm fuH. Peter Anvin
Reimplement FPU detection code in C and drop old, not-so-recommended detection method in asm. Move all the relevant stuff into i387.c where it conceptually belongs. Finally drop cpuinfo_x86.hard_math. [ hpa: huge thanks to Borislav for taking my original concept patch and productizing it ] [ Boris, note to self: do not use static_cpu_has before alternatives! ] Signed-off-by: H. Peter Anvin <hpa@zytor.com> Link: http://lkml.kernel.org/r/1367244262-29511-2-git-send-email-bp@alien8.de Link: http://lkml.kernel.org/r/1365436666-9837-2-git-send-email-bp@alien8.de Signed-off-by: Borislav Petkov <bp@suse.de> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2013-04-16x86: Fold-in trivial check_config functionBorislav Petkov
Fold it into its single call site. No functionality change. Signed-off-by: Borislav Petkov <bp@suse.de> Link: http://lkml.kernel.org/r/1365436666-9837-3-git-send-email-bp@alien8.de Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2013-04-02x86, cpu: Convert FDIV bug detectionBorislav Petkov
... to the new facility. Add a reference to the wikipedia article explaining the FDIV test we're doing here. Signed-off-by: Borislav Petkov <bp@suse.de> Link: http://lkml.kernel.org/r/1363788448-31325-4-git-send-email-bp@alien8.de Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2013-02-10x86 idle: remove 32-bit-only "no-hlt" parameter, hlt_works_ok flagLen Brown
Remove 32-bit x86 a cmdline param "no-hlt", and the cpuinfo_x86.hlt_works_ok that it sets. If a user wants to avoid HLT, then "idle=poll" is much more useful, as it avoids invocation of HLT in idle, while "no-hlt" failed to do so. Indeed, hlt_works_ok was consulted in only 3 places. First, in /proc/cpuinfo where "hlt_bug yes" would be printed if and only if the user booted the system with "no-hlt" -- as there was no other code to set that flag. Second, check_hlt() would not invoke halt() if "no-hlt" were on the cmdline. Third, it was consulted in stop_this_cpu(), which is invoked by native_machine_halt()/reboot_interrupt()/smp_stop_nmi_callback() -- all cases where the machine is being shutdown/reset. The flag was not consulted in the more frequently invoked play_dead()/hlt_play_dead() used in processor offline and suspend. Since Linux-3.0 there has been a run-time notice upon "no-hlt" invocations indicating that it would be removed in 2012. Signed-off-by: Len Brown <len.brown@intel.com> Cc: x86@kernel.org
2012-11-29x86, 386 removal: Remove CONFIG_X86_POPAD_OKH. Peter Anvin
The check_popad() routine tested for a 386-specific bug, and never actually did anything useful with it anyway other than print a message. Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Link: http://lkml.kernel.org/r/1354132230-21854-8-git-send-email-hpa@linux.intel.com
2012-11-29x86, 386 removal: Remove CONFIG_BSWAPH. Peter Anvin
All 486+ CPUs support BSWAP, so remove the fallback 386 support code. Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Link: http://lkml.kernel.org/r/1354132230-21854-5-git-send-email-hpa@linux.intel.com
2012-09-18x86, fpu: use non-lazy fpu restore for processors supporting xsaveSuresh Siddha
Fundamental model of the current Linux kernel is to lazily init and restore FPU instead of restoring the task state during context switch. This changes that fundamental lazy model to the non-lazy model for the processors supporting xsave feature. Reasons driving this model change are: i. Newer processors support optimized state save/restore using xsaveopt and xrstor by tracking the INIT state and MODIFIED state during context-switch. This is faster than modifying the cr0.TS bit which has serializing semantics. ii. Newer glibc versions use SSE for some of the optimized copy/clear routines. With certain workloads (like boot, kernel-compilation etc), application completes its work with in the first 5 task switches, thus taking upto 5 #DNA traps with the kernel not getting a chance to apply the above mentioned pre-load heuristic. iii. Some xstate features (like AMD's LWP feature) don't honor the cr0.TS bit and thus will not work correctly in the presence of lazy restore. Non-lazy state restore is needed for enabling such features. Some data on a two socket SNB system: * Saved 20K DNA exceptions during boot on a two socket SNB system. * Saved 50K DNA exceptions during kernel-compilation workload. * Improved throughput of the AVX based checksumming function inside the kernel by ~15% as xsave/xrstor is faster than the serializing clts/stts pair. Also now kernel_fpu_begin/end() relies on the patched alternative instructions. So move check_fpu() which uses the kernel_fpu_begin/end() after alternative_instructions(). Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Link: http://lkml.kernel.org/r/1345842782-24175-7-git-send-email-suresh.b.siddha@intel.com Merge 32-bit boot fix from, Link: http://lkml.kernel.org/r/1347300665-6209-4-git-send-email-suresh.b.siddha@intel.com Cc: Jim Kukunas <james.t.kukunas@linux.intel.com> Cc: NeilBrown <neilb@suse.de> Cc: Avi Kivity <avi@redhat.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2012-06-06x86/debug: Add KERN_<LEVEL> to bare printks, convert printks to pr_<level>Joe Perches
Use a more current logging style: - Bare printks should have a KERN_<LEVEL> for consistency's sake - Add pr_fmt where appropriate - Neaten some macro definitions - Convert some Ok output to OK - Use "%s: ", __func__ in pr_fmt for summit - Convert some printks to pr_<level> Message output is not identical in all cases. Signed-off-by: Joe Perches <joe@perches.com> Cc: levinsasha928@gmail.com Link: http://lkml.kernel.org/r/1337655007.24226.10.camel@joe2Laptop [ merged two similar patches, tidied up the changelog ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
2011-06-30x86-32, fpu: Fix DNA exception during check_fpu()Suresh Siddha
Before check_fpu() is called, we have cr0.TS bit set and hence the floating point code to check the FDIV bug was generating a DNA exception. Use kernel_fpu_begin()/kernel_fpu_end() around the floating point code to avoid this unnecessary device not available exception during boot. Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Link: http://lkml.kernel.org/r/1309479572.2665.1372.camel@sbsiddha-MOBL3.sc.intel.com Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2011-05-29x86 idle: deprecate "no-hlt" cmdline paramLen Brown
We'd rather that modern machines not check if HLT works on every entry into idle, for the benefit of machines that had marginal electricals 15-years ago. If those machines are still running the upstream kernel, they can use "idle=poll". The only difference will be that they'll now invoke HLT in machine_hlt(). cc: x86@kernel.org # .39.x Signed-off-by: Len Brown <len.brown@intel.com>
2010-05-07x86: Avoid check hlt for newer cpusJacob Pan
Check hlt instruction was targeted for some older CPUs. It is an expensive operation in that it takes 4 ticks to break out the check. We can avoid such check completely for newer x86 cpus (family >= 5). [ hpa: corrected family > 5 to family >= 5 ] Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com> LKML-Reference: <1273269585-14346-1-git-send-email-jacob.jun.pan@linux.intel.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-07-11x86/cpu: Clean up various files a bitAlan Cox
No code changes except printk levels (although some of the K6 mtrr code might be clearer if there were a few as would splitting out some of the intel cache code). Signed-off-by: Alan Cox <alan@linux.intel.com> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-31x86: fdiv bug detection fixKrzysztof Helt
The fdiv detection code writes s32 integer into the boot_cpu_data.fdiv_bug. However, the boot_cpu_data.fdiv_bug is only char (s8) field so the detection overwrites already set fields for other bugs, e.g. the f00f bug field. Use local s32 variable to receive result. This is a partial fix to Bugzilla #9928 - fixes wrong information about the f00f bug (tested) and probably for coma bug (I have no cpu to test this). Signed-off-by: Krzysztof Helt <krzysztof.h1@wp.pl> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-18x86: APIC: remove apic_write_around(); use alternativesMaciej W. Rozycki
Use alternatives to select the workaround for the 11AP Pentium erratum for the affected steppings on the fly rather than build time. Remove the X86_GOOD_APIC configuration option and replace all the calls to apic_write_around() with plain apic_write(), protecting accesses to the ESR as appropriate due to the 3AP Pentium erratum. Remove apic_read_around() and all its invocations altogether as not needed. Remove apic_write_atomic() and all its implementing backends. The use of ASM_OUTPUT2() is not strictly needed for input constraints, but I have used it for readability's sake. I had the feeling no one else was brave enough to do it, so I went ahead and here it is. Verified by checking the generated assembly and tested with both a 32-bit and a 64-bit configuration, also with the 11AP "feature" forced on and verified with gdb on /proc/kcore to work as expected (as an 11AP machines are quite hard to get hands on these days). Some script complained about the use of "volatile", but apic_write() needs it for the same reason and is effectively a replacement for writel(), so I have disregarded it. I am not sure what the policy wrt defconfig files is, they are generated and there is risk of a conflict resulting from an unrelated change, so I have left changes to them out. The option will get removed from them at the next run. Some testing with machines other than mine will be needed to avoid some stupid mistake, but despite its volume, the change is not really that intrusive, so I am fairly confident that because it works for me, it will everywhere. Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-05-25x86: janitor work in bugs.cMiklos Vajna
Just moved trailing statements to the next line, removed space before open/close parenthesis, wrapped long lines. Signed-off-by: Miklos Vajna <vmiklos@frugalware.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-04-06Fix booting pentium+ with dodgy TSCRusty Russell
We handle a broken tsc these days, so no need to panic. We clear the TSC bit when tsc_init decides it's unreliable (eg. under lguest w/ bad host TSC), leading to bogus panic. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-19remove mca-pentiumAdrian Bunk
This patch removes the mca-pentium boot option that was a noop. besides the source code cleanup factor, this saves some text as well: arch/x86/kernel/cpu/bugs.o: text data bss dec hex filename 651 77 4 732 2dc bugs.o.before 631 53 4 688 2b0 bugs.o.after Signed-off-by: Adrian Bunk <bunk@kernel.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30x86: convert TSC disabling to generic cpuid disable bitmapAndi Kleen
Fix from: Ian Campbell <ijc@hellion.org.uk> Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30x86: use CR0 defines.Dave Jones
Signed-off-by: Dave Jones <davej@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-13Delete filenames in comments.Dave Jones
Since the x86 merge, lots of files that referenced their own filenames are no longer correct. Rather than keep them up to date, just delete them, as they add no real value. Additionally: - fix up comment formatting in scx200_32.c - Remove a credit from myself in setup_64.c from a time when we had no SCM - remove longwinded history from tsc_32.c which can be figured out from git. Signed-off-by: Dave Jones <davej@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-11i386: move kernel/cpuThomas Gleixner
Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>